Add oauth_new: Complete OAuth authentication and comment system

- Created new oauth_new directory with clean OAuth implementation
- Added 4-tab interface: Lang, Comment, Collection, User Comments
- Implemented OAuth authentication with @atproto/oauth-client-browser
- Added comment posting functionality with putRecord
- Added proper PDS detection and error handling
- Skipped placeholder users to prevent errors
- Built comprehensive documentation (README.md, DEVELOPMENT.md)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

oauth_new/src/main.jsx

@@ -0,0 +1,5 @@
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import App from './App'
+
+ReactDOM.createRoot(document.getElementById('comment-atproto')).render(<App />)